Nanodiamond article and associated methods of fabrication

Abstract

A method for making a nanodiamond article includes applying an adhesion promoting layer to a substrate, and electrophoretically depositing a nanodiamond film on the substrate with the adhesion promoting layer thereon in a solution to make the nanodiamond article. The nanodiamond article may include a substrate, a nanodiamond film over the substrate, and the adhesion promoting layer between the substrate and the nanodiamond film.

Description

FIELD OF THE INVENTION[0001]The present invention relates to the field of nanodiamonds, and, more particularly, to the electrophoretic deposition of nanodiamond coatings (or films).BACKGROUND OF THE INVENTION[0002]The decreasing size and weight of modern electronic devices, coupled with the increasing performance demands, results in the packing of higher heat density producing electronics into a smaller space. Diffusion or extraction of this thermal energy may be a limiting factor in miniaturizing these heat producing electronics. Numerous novel approaches to thermal management at both the component and system level have been implemented in different electronic devices. For example, printed circuit boards may include copper thermal vias or thick, embedded metal layers or composites. These approaches, however, are often heavy and may result in marginal thermal performance enhancements compared to the baseline entity.[0003]Other thermal management techniques may include use of thick m...

AI Technical Summary

Benefits of technology

The patent describes a method for making a nanodiamond article by applying an adhesion promoting layer to a substrate and then depositing a nanodiamond film on the substrate using electrophoretical methods. The adhesion promoting layer helps the nanodiamonds stick to the substrate and can be formed using a film-forming amine. After depositing the nanodiamond film, it can be annealed at a high temperature. The resulting nanodiamond film has a thickness of greater than 30 microns and can be deposited on various substrates like electrical conductors. The technical effects of the patent include the improved adhesion of nanodiamonds to substrates and the ability to deposit thick nanodiamond films on various substrates.

Problems solved by technology

The decreasing size and weight of modern electronic devices, coupled with the increasing performance demands, results in the packing of higher heat density producing electronics into a smaller space.

Diffusion or extraction of this thermal energy may be a limiting factor in miniaturizing these heat producing electronics.

These approaches, however, are often heavy and may result in marginal thermal performance enhancements compared to the baseline entity.

Other thermal management techniques may include use of thick metallic spreaders, but those approaches likewise tend to be expensive, heavy, and sometimes have a long development lead time.

Graphite composites may be used, but the matrix phase reduces the effective thermal conductivity far below that of metals.

Heat pipes are efficient in carrying heat away from electronic devices but may have geometry limitations.

Additionally, some die carriers may incorporate copper alloys but are generally inadequate for high power applications consistent with low-SWAP (Size, Weight and Power) trends.

Diamonds or diamond-like materials are considered to have excellent thermal conductivity, but generally have geometry limitations and are relatively expensive.

A traditional diamond is difficult to machine and usually may not be placed where the diamond is desired for heat dissipation.

The costs associated with using traditional diamond are also exceptionally high given their rarity in the world and limited distribution.

There have been some diamond-like films that may be deposited via chemical vapor deposition, but this diamond deposition process is slow and unsuitable for thick, thermally conductive films.

Moreover, the actual crystallographic structures in those diamond films deposited by chemical vapor deposition are often more similar to an amorphous carbon substrate than actual diamond, and consequently, may not have adequate heat dissipation characteristics.

However, due to a general lack of control in placement of the nanodiamonds, they usually have been formed into 0-3 composites, where the nanodiamonds (small and “0” dimensional) are inserted into another material resulting in a three-dimensional matrix.

Additionally, the properties of this type of composite are isotropic, i.e., the composite cannot be used to preferentially direct heat or electrical flow.

The enhanced and anisotropic properties that would be provided by a nanodiamond coating as a 2-2 composite have not yet been obtained using nanodiamonds.

Often the particles may not adequately adsorbed onto the substrate surface without proper chemical and physical modification to the substrate, similar to how surfaces are modified for sputtering or electroplating adhesion.

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